A solar startup company contacted Owens Design, Fremont, Calif., about building an automated process assembly tool for its photovoltaic (PV) cell manufacturing operation. Owens Design provides equipment design and manufacturing services to machine builders in the semiconductor, solar, data storage and other emerging technology industries.
The Rockwell Automation Integrated Architecture provided the design speed, efficiency and off-theshelf components Owens Design needed to meet the customer’s tight delivery timeframe.
In the PV cell manufacturing operation, the tool needed to accurately punch a pattern of holes into a plastic interconnect material at high speed, cut it to length, and then place the cell components into carrier trays for the next operation. The machine would need an advanced vision system at the input and output to inspect for surface and dimensional defects and provide positional feedback for the robotics.
The solar company had demonstrated the process with manual tools and now turned to Owens Design to build an automated version that could meet its high throughput demands. The end user had an aggressive delivery schedule. Adding to the challenge was the need to integrate a variety of third-party components into the tool design, including stepper motors, pneumatic manifolds, RFID tag readers and smart cameras.
The engineers at Owens Design chose the Rockwell Automation Integrated Architecture and EtherNet/IP as the controls foundation for the assembly tool. EtherNet/IP is a widely used industrial Ethernet protocol that uses standard unmodified Ethernet to manage real-time control and information flow from the machine-level to the IT enterprise.
“The use of an EtherNet/IP network to connect third-party components would help streamline assembly, reduce wiring costs and simplify integration of our tool into the customer’s manufacturing operation,” said Doug Putnam-Pite, Director of Software Development, Owens Design. Equally important was the need to use advanced servo motion control technology that would give the tool the required speed, accuracy and versatility.
For the precise machine movements and positioning, the engineers used an Allen-Bradley Kinetix Integrated Motion system with an Allen-Bradley ControlLogix programmable automation controller (PAC) and Kinetix 6000 multi-axis servo drives. Together they coordinate and control all major functions of the assembly tool, including cutting and hole punching tasks, guiding and feeding of the interconnect material, and placement of the processed components into the carrier trays.
The Rockwell Automation Integrated Architecture provided a platform to create motion and machine control using one programming environment. An extensive motion instruction set is embedded in the ControlLogix controller and is programmed using the Rockwell Software RSLogix 5000 programming software. It lets you configure motion and sequential control in one package, speeding application development and lowering overall cost.
The Kinetix servo drives deliver the precise positioning needed to accurately guide the interconnect material as the tool punches, cuts and places the processed material into the carrier trays at high speed.
EtherNet/IP is used to connect to third-party components. Multiple discrete wires were replaced by one EtherNet/IP cable to integrate intelligent components like a vision camera or RFID tag into the control system.
“The ability to distribute components throughout the tool proved to be a huge timesaver,” said Bob Fung, Vice President of Engineering. “We simply placed the components where they were needed along the length of the tool. This dramatically reduced our wiring cost and helped speed installation and commissioning.”
Two Allen-Bradley SmartGuard 600 controllers, linked through EtherNet/IP, perform a variety of safety monitoring and control functions and seamlessly link to other machine control devices. An Allen-Bradley Stratix 8300 managed switch helps ensure proper network segmentation, allowing the end user to integrate multiple cell zones across the plant while helping to achieve secure integration at the enterprise level.
The solar company working with Owens Design needed a control system with high performance and ease of connectivity for their automated process assembly.
“During the design phase, the Rockwell Automation programming environment let us divide the project into separate modules and have people work on them independently, which is not possible with some other systems,” Putnam-Pite said. “This helped speed system engineering and configuration.”
The ease of integration was an advantage. Through EtherNet/IP, the engineers connected a variety of low cost, off-the-shelf components into the system – many of which included add-on profiles to RSLogix 5000. This eliminated the need to write custom drivers for each device, helping the engineers reduce engineering time by 30%.
By leveraging EtherNet/IP, technicians connected one communications cable and power line between the main cabinet and remote I/O modules. By placing the I/O close to the individual devices, the engineers eliminated hundreds of feet of cable and much of the repetitive hardwiring, helping to reduce installation time by approximately 40%.
“The plug-and-play connectivity of the Rockwell Automation Integrated Architecture gave us the design speed and efficiency we needed to meet the customer’s tight delivery timeframe, along with the ability to take advantage of the wide selection of off-the-shelf components,” said Bob Fung, Vice President of Engineering at Owens Design. “This allowed us to deliver a robust, reliable and more tightly integrated system.”
Filed Under: Factory automation, Energy management + harvesting, Green engineering